Device for clearing blocked pipes

ABSTRACT

A device for use in clearing blocked pipes, drains and other conduits comprises a hollow body portion, means to receive a bottle or cartridge of compressed gas which means are operable to feed a controlled quantity of gas from the bottle or cartridge into the hollow body portion, a valve controlled outlet from the hollow body portion to an outlet conduit, and a liquid inlet to said outlet conduit with a non-return valve therein, the outlet being connectable to a blocked conduit so that liquid may be passed into the said outlet conduit and the blocked conduit through the said liquid inlet to fill the blocked conduit as far as the blockage and gas fed into the hollow body and held under pressure therein may be rapidly released therefrom by actuation of the valve and applied against the liquid in the conduits to impart a shock to the liquid.

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7 a. I tlmtetl States atent 1 [111- 3,789,861

Conn et al. Feb. 5, 1974 DEVICE FOR CLEARING BLOCKED PlPES [75] Inventors: Jack Samuel Conn, Primary Exam",1er 'A]?n Cohan d Walton-on-Thames; Lionel Ralph jsmmm Z FR fi i & M Fabien, London, both of England ttorney, gent, or zrmaw inney aw inney [73] Assignee: Surrey Steel Components Limited, Surrey, England 22] Filed: May 8, 1972 [57] ABSTRACT PP 251,397 A device for use in clearing blocked pipes, drains and other conduits comprises a hollow body portion, {30] Foreign Application Priority Data means to receive a bottle or cartridge of compressed M 10 1 971 Great Britain 14 020/71 gas which means are operable to feed a controlled ay quantity of gas from the bottle or cartridge into the hollow body portion, a valve controlled outlet from [52] US. Cl 134/166 C, 15/406, the hollow body portion to an Outlet conduit, and a gg- ;geg gggggggg $2132 1255;; 312 ififfiiig 25221822811"??? 2 2 327 5 240 13/1 66 blocked conduit so that liquid may be passed into the 6 c C 169 said outlet conduit and the blocked conduit through the said liquid inlet to till the blocked conduit as far as the blockage and gas fed into the hollow body and [56] References Cited held under pressure therein may be rapidly released UNITED STATES PATENTS therefrom by actuation of the valve and applied 3,426,774 2/1969 Conn 222/5 X against the liquid in the conduits to impart a shock to 3,203,226 aorwitlt et al )C( th li id 2,82 ,4 7 l attic FOREIGN PATENTS OR APPLICATIONS 6 (Jaims, 4 Drawing Figures 971,161 9/l964 Great Britain 222/5 PATENTED 5W4 3,789,861

sum 2 [1F 2 DEVICE FOR CLEARING BLOCKED PIPES I The invention relates to devices for use in clearing blocked pipes, drains and other conduits of the kind in which a sudden application of gas pressure is employed to impart a shock to liquid in the conduit and lying against the blockage.

The invention provides a device for use in clearing blocked pipes, drains and other conduits comprising a hollow body portion, means to receive a bottle or cartridge of compressed gas which means are operable to feed a controlled quantity of gas from the bottle or cartridge into the hollow body portion, a valve controlled outlet from the hollow body portion to an outlet conduit, and a liquid inlet to said outlet conduit with a nonreturn valve therein, the outlet being connectable to a blocked conduit so that liquid may be passed into the said outlet conduit and the blocked conduit through the said liquid inlet to till the blocked conduit as far as the blockage and gas fed into the hollow body and held under pressure therein may be rapidly released therefrom by actuation of the valve and applied against the liquid in the conduits to impart a shock to the liquid.

A pressure gauge or other pressure indicator may be fitted to the hollow body to assess the pressure resultant from the quantity of gas fed into the hollow body.

The means to receive the bottle or cartridge of compressed gas may be arranged to pierce the bottle or cartridge, and may include a control valve for feeding a controlled quantity of gas from the pierced bottle or cartridge to the hollow body portion.

The bottle or cartridge may contain carbon dioxide. It may for example be a cartridge of the kind commonly employed for making soda water in the home. The body portion may be provided with a pistol grip handle and the means for receiving the cartridge may comprise a chamber within the handle.

The chamber may contain a socket to receive the neck of the cartridge, and a needle within the socket to pierce the cartridge, the said control valve being operable to release gas from the said cartridge.

Means may be provided to seal the chamber and the chamber may be in communication with the hollow interior of the body portion, the control valve being operable to feed gas out of the cartridge and into the chamher.

The chamber may be sealed by a plug. The plug may be a screw-threaded plug operable to force the cartridge onto the needle in the socket. Different size cartridges may be accommodated by providing different length plugs, or a single plug variable in length.

The device amy include a trigger arranged to open the valve controlling the outlet from the body portion.

A specific embodiment of a device according to the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a part section through the device;

FIG. 2 is a rear view partly in section, of the device shown in FIG. 1;

FIG. 3 is a section through part of the handle of the device; and

FIG. 4 is a section through the pressure indicator of the device.

The device comprises a body having an outlet conduit or barrel 1] at one end and a pistol grip handle 9 at the other end. The barrel 11 may be inserted directly, or through a pipe extension, into a blocked pipe to be cleared. Suitable sealing means such as expansion (not shown) may be provided between the outlet pipe or extension and the blocked pipe. Alternatively or in addition adaptor plugs may be used. The plugs may be gripped between two washers 7, 8, threaded onto the screw-threaded end 6 of the barrel 11. Although the device will normally be portable and be connected into a blocked system as and when required, it may be permanently connected into a system which is particularly liable to blockage.

The barrel 11 has an inlet 12 for water to provide a fluid column in the barrel and in the blocked pipe as far as the blockage. There is an automatic non-return valve 13 in the inlet. The inlet is intended for a hose connection to a water tap.

The body 10 is hollow and has an outlet 4 leading to the barrel 11. The handle 9 has a chamber 5 therein which communicates with the hollow body 10 via passage 14.

The outlet 4 is controlled by a valve member 16 rapidly operable by a trigger 17 connected to the valve 16 by a rod 19 to which the valve member 16 is attached, the rod being pivotally connected to the trigger and passing through a sealing gland 18.

A spider 21 connected to the valve 16 slides in the barrel 1 1 and supports the valve when in the open position.

The chamber 5 is sealed by a removable screwthreaded plug 14a, and at the base of the chamber there are means 15 to locate a gas cartridge 20. These means 15 are shown in more detail in FIG. 3 and comprise a socket member 22, an end cap 23 and an operating lever 25.

The member 22 has a screw-thread 26 and is screwed into the bottom end of the chamber 5. A sealing ring 27 is provided around the member, and a grub screw 28 secures the member firmly in the bottom of the chamber 5.

In the socket of the socket member is a sleeve 29 and a washer 30. The washer 30 has an aperture 31 therein through which a spring loaded needle 32 protrudes. The needle is fitted into a sleeve 33 which is arranged slideably in a bore 34 in the socket member 22, and is surrounded by a sealing ring 35. A spring 36 acting between the end of bore 34 and a washer 37 located in I sleeve 29 and around needle 32, urges the sleeve 29 and needle 32 away from the socket of the socket member.

At the lower end of the sleeve 29 there is a ball 38 seating in a socket in the sleeve and abutting the ball is a cam 39 carried by lever 25 and rotatable with the lever abut the lever axis 40. The device is loaded by placing a cartridge 20 in th chamber 5, neck downwards, and screwing in the plug 14. This urges the neck of the cartridge into the socket of socket member 22 and the needle 32 pierces the cartridge. Gas may be fed from the cartridge to the hollow body 10 by pressing lever 25. This causes cam 39 to allow sleeve 33 and needle 32 to move downwardly in the socket member under the action of spring 36, and gas escapes into chamber 5. The lever 25 is biased outwardly by a spring 43 and when released it returns to the off position. Plug includes a packing piece 14b which may be removed to accommodate a larger gas cartridge.

A safety relief valve 41 is provided. (FIG. 3).

A pressure indicator 42 is provided and is shown in more detail in FIG. 4. The indicator comprises essentially a housing 50, shaft 51 and end cap 52. The housing has two bores 53, 54 therein, bore 53 being of larger diameter and the two bores being linked by a conical section 55. Tapered flutes 56 are arranged around section 55.

The outer surface of the portion defining bore 53 is screw threaded at 57 and 58 and has an annular flange 59. Four uniformly spaced radial passages 60 in flange 59 communicate with bore 53. I

The right hand end of shaft 51 is arranged to slide in bore 54. Four uniformly spaced longitudinal channels 61 permit the right hand end of bore 54 to communicate with an annular cut away portion 62. Another cut away portion 53 of the shaft houses an O-ring 63.

The left hand end of shaft 52 lies within bore 53 and is surrounded by a compression spring 64. End cap 52 is screwed onto threads 57 and spring 64 acts between the cap and a flange 65 to urge shaft 51 to the right.

A reduced chamber portion 66 of shaft 51 protrudes from an aperture 70 in cap 52. Portion 66 has three graduation markings 67 thereon corresponding to high, medium and low pressure respectively The higher the pressure in the body of the device, the higher will be the pressure in annular recess 62, and the more shaft 51 will move to the left against the action of spring 64. Thus the degree of protrusion of portion 66 from aperture 70 gives a measure of the pressure within the device.

The pressure indicator serves as an additional pressure safety relief valve. if the high pressure reading 67 is exceeded the O-ring 63 is moved by shaft 51 into a position in which gas can escape into bore 53 between flutes 56, and can thus bleed to atmosphere through passageways 60. The maximum pressure may be in the range 200-300 psi.

In use, the barrel 11 is connected to the blocked pipe, the pipe is filled with water as far as the blockage through the inlet 12 and the lever 43 is then pressed to admit a controlled charge of gas to the hollow body 10. When the pressure indicator gives the desired reading, the lever 43 is released. Finally and while the device is supported against recoil, the valve 16 is rapidly opened so that the gas pressure imparts a shock to the liquid column.

There is a return spring 44 for the valve 16 and it is desirable that the strength of this spring is sufficient to close the valve-against the pressure of the water supply to prevent the cylinder being filled with water.

The barrel is fitted with a bleed screw 24.

The pressure at which lever 43 is closed may be chosen according to the degree of seriousness of the blockage.

A secondary use of the device is in testing under static pressure, installations such as central heating installations or household plumbing. For this purpose the installation is filled with water, the outlet of the device is sealed thereto, the gas pressure is developed in the body and applied to the installation. The loss of pressure is then an indication of leakage.

In this case the valve 16 may be opened slowly.

The invention is not restricted to the features of the foregoing example. For instance if desired the chamber may be fitted with a second valve controlled gas inlet so that gas may be supplied independently of the bottle 31 e.g. from a compressed air supply.

Furthermore the safety valve 41 may be dispensed with.

We claim:

1. A device for use in clearing blocked pipes, drains and other conduits, comprising:

a. a hollow body portion;

b. a pistol grip handle on said body portion and including c. a chamber which is in communication with said hollow body portion;

d. means within said chamber for receiving a cartridge of compressed gas;

e. means within said handle for engaging said cartridge for releasing gas therefrom into said chamber;

f. an outlet conduit for said hollow body portion, said outlet conduit including, external to said hollow body portion, a liquid inlet;

g. a non return valve in said liquid inlet;

h. an outlet valve in said outlet conduit for releasing gas in said hollow body portion through said outlet conduit; and

i. a trigger mounted on said body portion and connected to said outlet valve in said outlet conduit for releasing said outlet valve.

2. A device as claimed in claim 1 in which a pressure gauge or other pressure indicator is fitted to the hollow body.

3. A device as claimed in claim 2 in which the pressure indicator comprises a plunger spring urged towards a datum position, gas pressure within the hollow body acting on the plunger to urge the plunger away from the datum position.

4. A device as claimed in claim 3 in which the plunger carries an O-ring which normally seals the body, but when the pressure in the body exceeds a predetermined value, the O-ring is carried by the plunger into a conical fluted chamber permitting gas to escape between the O-ring and flutes, and hence to atmosphere.

5. A device as claimed in claim 1 wherein said means for receiving the cartridge comprises:

a. means for receiving a neck of a bottle-shaped cartridge;

b. a screw threaded plug mounted in said handle for advancement towards an engagement with the base of said cartridge; and

c. an operating member connected to 'said screw threaded plug and disposed externally of said handle.

6. A device as claimed in claim 5 in which said means for engaging said cartridge comprise:

a spring loaded needle for piercing said cartridge as said plug is screwed towards and engages the base of said cartridge;

and wherein said handle includes:

a. a manually operable lever; and 1 b. means connecting said lever and said needle fo displacing said needle to release gas from said cartridge into said chamber. 

1. A device for use in clearing blocked pipes, drains and other conduits, comprising: a. a hollow body portion; b. a pistol grip handle on said body portion and including c. a chamber which is in communication with said hollow body portion; d. means within said chamber for receiving a cartridge of compressed gas; e. means within said handle for engaging said cartridge for releasing gas therefrom into said chamber; f. an outlet conduit for said hollow body portion, said outlet conduit including, external to said hollow body portion, a liquid inlet; g. a non return valve in said liquid inlet; h. an outlet valve in said outlet conduit for releasing gas in said hollow body portion through said outlet conduit; and i. a trigger mounted on said body portion and connected to said outlet valve in said outlet conduit for releasing said outlet valve.
 2. A device as claimed in claim 1 in which a pressure gauge or other pressure indicator is fitted to the hollow body.
 3. A device as claimed in claim 2 in which the pressure indicator comprises a plunger spring urged towards a datum position, gas pressure within the hollow body acting on the plunger to urge the plunger away from the datum position.
 4. A device as claimed in claim 3 in which the plunger carries an O-ring which normally seals the body, but when the pressure in the body exceeds a predetermined value, the O-ring is carried by the plunger into a conical fluted chamber permitting gas to escape between the O-ring and flutes, and hence to atmosphere.
 5. A device as claimed in claim 1 wherein said means for receiving the cartridge comprises: a. means for receiving a neck of a bottle-shaped cartridge; b. a screw threaded plug mounted in said handle for advancement towards an engagement with the base of said cartridge; and c. an operating member connected to said screw threaded plug and disposed externally of said handle.
 6. A device as claimed in claim 5 in which said means for engaging said cartridge comprise: a spring loaded needle for piercing said cartridge as said plug is screwed towards and engages the base of said cartridge; and wherein said handle includes: a. a manually operable lever; and b. means connecting said lever and said needle for displacing said needle to release gas from said cartridge into said chamber. 